Abnormal staircase-like I-V curve in InGaN quantum well solar cells

Abstract

InGaN/GaN multiple quantum well-solar cells with different barrier thicknesses have been comparatively studied, and it is demonstrated that a thinner barrier facilitates the transport of photogenerated carriers. Meanwhile, an abnormal but regular staircase-like I-V curve is observed. The induction factors and microscopic physical process relevant to this abnormal feature are analyzed in detail, which is found closely related to the inadequate internal field and special epitaxial structure. Furthermore, the formation conditions of I-V curves with various types of inflections are also proposed. This work provides insight into the origin of device problems, which can be applicable to other types of solar cells.